This invention relates to a scanning type exposure apparatus and, in particular, to a scanning type exposure apparatus for equalizing in-plane exposure quantity.
Referring to FIG. 1, a conventional scanning type exposure apparatus will first be described.
In FIG. 1, an exposure light beam 2 is outputted from a light source 1, such as a laser and a lamp. The exposure light beam 2 passes through an optical system 3, such as a lens, and is introduced into a substrate 4 on a substrate stage.
With such a structure, an exposure area is controlled by the use of a reticle blind 5. Further, the exposure light beam 2 irradiates a surface of the reticle 6. The exposure light beam 2 passing the reticle 6 illuminates the surface of the substrate 4.
In such a scanning type exposure apparatus, the reticle 6 is scanned in the direction indicated by the arrow illustrated in FIG. 1, while the substrate 4 is reversely scanned in synchronism with the reticle 6.
Under this circumstance, a pattern on the reticle 6 is sequentially transferred onto the substrate 4.
For example, this kind of scanning type exposure apparatus is disclosed in Japanese Unexamined Patent Publication No. Hei. 7-142313.
However, each illuminance is uniform in each region of the substrate having a wide area in the above-mentioned conventional scanning apparatus.
Consequently, it is difficult to accurately transfer the pattern when the pattern is further reduced in size.

It is therefore an object of this invention to provide a scanning type exposure apparatus which is capable of keeping in-plane illuminance uniform in a substrate having a wide area.
It is another object of this invention to provide a scanning type exposure apparatus which is capable of accurately transferring a fine pattern.
In a scanning type exposure apparatus according to this invention, an illumination light beam from a light source through an opening portion of a reticle blind is introduced onto a reticle.
Further, a pattern on the reticle is sequentially transferred onto the substrate by scanning the reticle and the substrate, respectively.
Under this circumstance, the substrate is divided into a plurality of regions along a scanning direction.
Moreover, a variable unit for changing an opening area of the opening portion of the reticle blind is arranged so as to substantially equalize integrated exposure quantity in each region.
In this case, the variable unit is controlled in synchronism with the scanning of the reticle and the substrate.
In another scanning type exposure apparatus according to this invention, an illumination light beam from a light source through an opening portion of a reticle blind is introduced onto a reticle.
Further, a pattern on the reticle is sequentially transferred onto the substrate by scanning the reticle and the substrate, respectively.
With such a structure, the reticle blind forms the opening portion by overlapping a first light shielding plate with a second light shielding plate.
Further, a side parallel to the scanning direction of the opening portion constitutes one side of the opening portion formed in the first light shielding plate.
Moreover, the length of a side perpendicular to the scanning direction of the opening portion of the reticle blind is determined on the basis of the second light shielding plate.
In the scanning type exposure apparatus, a driving unit is arranged so as to drive either the first or second light shielding plate in synchronism with the scanning of the reticle and the substrate.
In this event, the length is determined on the basis of an adjusting region provided at one side portion parallel to the scanning direction of the second light shielding plate.
Alternatively, the length may be determined on the basis of adjusting regions provided at both side portions parallel to the scanning direction of the second light shielding plate.